CO-117 denial code
Transportation is only covered to the closest appropriate facility
How to fix it
Appeal with documentation that closer facilities could not provide the required level of care.
How to prevent it
Document the clinical reason for facility selection at the time of transport.
In practice
An ambulance transports a patient past two closer hospitals to a facility with a cardiac catheterisation laboratory. The claim returns CO-117, because coverage extends only to the nearest appropriate facility.
The word doing the work is appropriate. Coverage is not limited to the geographically nearest hospital but to the nearest one able to provide the care the patient needed, and the two are frequently different.
The appeal turns on documenting why the closer facilities could not provide that care — no interventional capability, no available bed, no specialty coverage on that night. Recorded at the time of transport, that documentation usually carries the appeal.
What sits behind it
The determination is made by an edit comparing distances, not by anyone assessing capability. That is why genuinely correct transports get denied and why the appeal is often successful: it supplies clinical reasoning the automated check could not perform.
Contemporaneous documentation is what separates a successful appeal from a failed one. A run report noting that the nearest facility was on diversion, or lacked the required service line, is persuasive. The same assertion made three months later in an appeal letter is much less so.
Specialty destination protocols help substantially where they exist. Regional systems designating trauma, stroke, cardiac and burn centres create a documented standard for bypassing closer hospitals, and citing the applicable protocol in the appeal moves it from clinical judgement to established policy.
Related codes
Terms used here — Medical Necessity · Appeal · Denial
How we handle it — Denial Management · Claims Management · Revenue Cycle Management
Primary sources
The rules behind CO-117, at the bodies that publish them.
- Medicare Coverage Database (LCD/NCD) (opens in a new tab)
Centers for Medicare & Medicaid Services — Searchable national and local coverage determinations. The direct answer to whether a diagnosis supports medical necessity for a given procedure.
- Medicare Benefit Policy Manual (opens in a new tab)
Centers for Medicare & Medicaid Services — What Medicare covers and under what conditions, as distinct from how a claim is processed. The starting point for any coverage or medical necessity question.
- Advance Beneficiary Notice of Noncoverage (ABN) (opens in a new tab)
Centers for Medicare & Medicaid Services — The form and the rules for issuing it. Whether a non-covered service can be billed to the patient usually turns on whether a valid ABN was obtained beforehand.
Looking for a different code? Search all 190 CARC and RARC codes
Questions about CO-117
No — it means the nearest facility appropriate to the patient's needs. A hospital without the required capability is not appropriate regardless of distance, which is why transports past closer facilities are frequently correct and frequently denied by an edit that only measures distance.
A contemporaneous run report recording why closer facilities were bypassed — diversion status, absent service line, unavailable specialty coverage. Written at the time it is persuasive; asserted months later in an appeal letter without contemporaneous support it usually is not.
Considerably. Where a regional system designates trauma, stroke, cardiac or burn centres, citing the applicable protocol converts the argument from individual clinical judgement to documented regional policy, which reviewers accept far more readily.
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